SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3156de93a6bfd28368108cc3e17bb5706a23fd8d42b34d422e3c1bfc4841293' 
  AND token = 'BqvniaqYUge6Sz0JdB8sdOXnxjyg55X5Q0BeoL44/mw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}